1. Field of the Invention
The present invention relates to a mobile body that moves along a movement path in which a plurality of pairs of magnetic poles, each including a north pole and a south pole, are arranged, by using a linear motor.
2. Description of the Related Art
There has been known a mobile body system including a mobile body having a linear motor and a magnetic pole path in which a plurality of pairs of magnetic poles, each including a north pole and a south pole, are arranged. In this kind of mobile body system, the linear motor is driven by magnetic interaction with a magnetic flux of the magnetic pole path, and the mobile body thereby moves along the magnetic pole path.
Meanwhile, in this kind of mobile body system, a magnetic pole path may have a magnetic pole missing section in which the magnetic pole is missing.
In this respect, there is a mobile body system in which a mobile body includes two linear motors, two magnet absence detecting sensors (e.g., photo sensors), and two position detecting sensors (e.g., Hall elements). The two magnet absence detecting sensors and the two position detecting sensors are provided in the mobile body, respectively corresponding to the two linear motors. In this mobile body, when one magnet absence detecting sensor detects one linear motor being located in the magnetic pole missing section, switching is made to the other linear motor, to enable continuous driving. Further, in this mobile body, when it is detected that one position detecting sensor is located in the magnetic pole missing section, switching is made to the other position detecting sensor, to enable continuous position detection for the mobile body.